SIP ALG stands for Session Initiation Protocol Application Layer Gateway and is a setting you can find on most routers that can affect SIP packets that pass through the network. This can have an adverse effect, causing issues such as ghost calls, one-way audio or call connection issues. It’s recommended to turn this setting off.
I’m having issues making and receiving calls, what can I do?
There are numerous reasons why this could be happening. It could be an issue with your broadband, the VoIP device you’re using or with your account configuration. If you’re still unsure, feel free to contact our support team and we’ll do our best to investigate what the issue is.
I have bad audio on calls, could this be a fault with my broadband?
Yes, the most common cause of call audio quality issues is the quality and capacity of the Internet connection. The first port of call would be to check your Internet connection using a speed test. You can also reboot the router as this commonly resolves some issues. If your tests come back ok or you need any other advice, we can run a trace on your Internet connection to discover what the issue could be.
Do I need to reconfigure my firewall?
You shouldn’t need to unless you have previously changed the default firewall settings to a more specific configuration (such as in a managed office environment). With few exceptions, VoIP traffic works fine with default firewall settings.
What happens if my Internet goes down, can I still take calls?
If your VoIP device is not connected to the Internet, it will not be able to receive calls, but you can choose to forward calls to an external number in the meantime, ensuring you can continue to take calls. You can do this from your online control panel. If you have a widespread issue and cannot access the Internet at all, contact our support team and they’ll be able to assist.
How much bandwidth do VoIP calls need?
You need a minimum of 150kbps (that’s 0.15 Mbps) up and down for a single VoIP phone and an additional 120kbps (0.12 Mbps) for each additional phone you have.
I’ve been advised to turn off SIP ALG, how do I do this?
Each router will have a different method to accessing SIP ALG settings. Some will have a designated setting in your router control panel whereas others you will need to Telnet in. On rare occasions, the router will not give you the option of turning SIP ALG off at all, in which case you would need to replace the router with one that does.